11 Toothy Facts About Gharials

Once a widespread predator, the strange, skinny-jawed gharial is now critically endangered and has been restricted to a handful of Nepalese and northern Indian rivers. Here’s everything you should know about the world’s most unusual crocodilian.


When a male of this species gets to be around 10 years old, a bulbous knob will start to emerge just behind his nose. (More about that in a minute.) Scientists refer to the knob as either the ghara or gharal. Both terms—along with the animal’s common name—are descended from the Hindi word ghara, which is a round earthenware pot. A common sight in India and Nepal, ghara pots bear a passing resemblance to the gharial’s snout. 



The gharial is the only living crocodilian that is visibly sexually dimorphic beyond body size: Females don’t have the aforementioned gharas. At around 11 to 14.5 feet long, they're also much smaller than the males, which typically range from 16 to 19.5 feet in length. Some monstrous, 21-foot male specimens have been documented. Such huge individuals can weigh a whopping 1500 pounds, making them some of the heaviest reptiles on Earth. And yet in weight, they're completely upstaged by the famous saltwater crocodile, which can weigh more than a ton.


Whereas most crocodilians have rather broad snouts, a gharial’s is so long and thin that it looks like a toothy broomstick. Comical as these jaws may seem, the slender shape is perfectly designed for snapping up the animal’s favorite food: fish. The gharial snout can rapidly slice through the water with minimal resistance, and its jaws are equipped with 106 to 110 needle-like teeth, which interlock when the crocodilian snaps its mouth shut—impaling any fish that happen to be between its jaws.

As it grows, a gharial’s snout changes shape, and its diet evolves accordingly. Since hatchlings have broader jaws than adults do, the youngsters mainly eat insects, crustaceans, and frogs. Over time, their snouts get thinner and longer and become ill-suited for snapping up the large land animals that other crocodilians tend to pursue. Full-grown gharials almost exclusively dine on fish, although big individuals sometimes gulp down the occasional bird, reptile, or small mammal.


With their specialized jaws, gharials just aren’t built to take down big land animals—including us. Attacks on people are exceptionally rare—only a handful have ever been reported, and most cases implicate either a mother gharial who was protecting her nest or an irate specimen that had gotten tangled up in somebody’s fishing net. Not one of these interactions resulted in the loss of human life.

Still, while the beasts don’t kill people, they do scavenge our cadavers. Homo sapiens remains have been found inside gharial stomachs, along with bracelets and jewelry. Corpses are regularly sent down the Ganges river as part of a Hindu funerary custom, and to the gharials that stalk these waters, lifeless bodies make for easy targets. There's another benefit to eating humans, too: Like all reptiles, gharials can’t chew and must gulp down their meals in large chunks. In order to better process its meals, a gharial will swallow hard objects like rocks, which, within the stomach, jostle around and mash up undigested chow. Some theorize that the crocodilians might be deliberately swallowing human jewelry because it helps them to digest real food.


The ghara, which mainly consists of cartilage, is attached to a flap that partially covers the nostrils. Taken as a whole, this apparatus acts like a resonating chamber. When the male exhales, the flap starts vibrating, which can produce a long-range buzzing noise. It’s believed that this sound is used to communicate with females in mating season. Furthermore, males blow bubbles through their gharas during the courtship ritual.


Normally, crocodilians keep their legs sprawled out to the sides on dry land. However, most species can also do what’s known as a “high walk.” To do so, the animals straighten their legs and raise their bellies high above the ground; this allows a crocodile or alligator to stride across rocky terrain without scratching up its underside. In general, the high walk is reserved for short forays, although some crocs—particularly juveniles—will use it during long-distance treks as well.

But to gharials, high walking isn’t an option. Compared to other crocodilians, this species has abnormally weak limb muscles—so when they're on land, gharials must resort to pushing themselves along on their stomachs. They're much better suited to swimming, and, in fact, it’s been argued that the gharial is the world’s most aquatic crocodilian. By and large, gharials only ever haul themselves ashore to bask or to lay their eggs.


Once they reach sexual maturity at age 10, female gharials are inducted into a harem. Usually, these groups consist of four to six members who are jealously guarded by a resident bull male. Come mating season—which lasts from December to January—the resident bull breeds with all the females and fights to keep rival males at bay. Later, as the water levels recede during the dry months (March to May), the nesting season begins.


Gravid females looking to dig their nests will seek out deep sand banks, and the beaches of small, mid-river islands are considered ideal—predators will be less likely to disturb the eggs there. Using mainly her hind limbs, the female will create a pitcher-shaped burrow into which she'll deposit anywhere from 30 to 50 eggs. On average, each weighs about a third of a pound, making them the biggest eggs produced by any crocodilian

Throughout the incubation period, the gharial will spend every night sitting beside her nest and every day keeping a close eye on it. Finally, after about 70 days, the eggs hatch into chirping, foot-long babies. Hearing their cries, the mother helps dig the newborns out of their burrow. They’ll spend a few months under her protection before striking out on their own.


Junkyardsparkle, Flickr // CC0

Present-day crocodilians are divided into three groups. First, there’s the aligatoridae family, which—as the name suggests—includes alligators, along with caimans. Meanwhile, all “true” crocodiles (for example, saltwater and Nile crocs) are contained within another group called the crocodylidae. Last but not least is the third and final subgroup, the gavialidae.

Traditionally, the gharial has been regarded as the only extant member of this last bunch. Yet, some experts believe that another gavialid is wandering around out there. The creature in question is Tomistoma schlegelii, also known as the false gharial (pictured above). A native of southeast Asia, this endangered reptile can grow longer than 16 feet and weigh more than 450 pounds. Like its namesake, the false gharial has a long, slender snout filled with needle-shaped teeth. Yet, despite these features, it’s long been classified within crocodylidae.

Until fairly recently, most biologists believed that this animal’s resemblance to the true gharial was 100 percent superficial. However, some new information has forced scientists to reconsider the relationship between these two predators. Molecular data suggests that Tomistoma should, in fact, be regarded as a member of the gavialidae family. Still, many scientists aren’t sold. At the anatomical level (and in the fossil record), false and true gharials are quite different—especially in terms of tail and jaw musculature. Given all the contradictory evidence we have to sort through, it looks like this debate won’t be settled anytime soon.


Juveniles tend to frequent side streams and tranquil backwaters. Mature gharials, on the other hand, are usually found in deep, fast-flowing rivers. Most of their time is spent in the calmer sections of these bodies, away from the high-velocity currents. Adults are especially fond of river bends and confluences, where they’re known to gather en masse.


Overfishing, poaching, and habitat loss are all contributing to the decline of this species. Invasive prey items also bear some of the blame. In an attempt to boost the local fishing industry, African tilapia have been deliberately released into Indian rivers since the 1950s. It turns out that the foreign fish are terrible for gharials, which can die of gout after eating them. It’s believed that the tilapia contained chemicals from polluted rivers and when the gharials ate them, the toxins became concentrated, leading to gout. Or it’s possible that some unidentified toxin could be to blame.

Factors like these have put the gharial’s long-term survival in jeopardy. For millennia, they patrolled the rivers of Pakistan, Myanmar, Bangladesh, and Bhutan. But over the past century, they’ve gone extinct in all four countries. Today, the species occupies just 2 percent of its former range. According to the World Wildlife Federation, a meager 1100 wild gharials currently reside in India, while fewer than 100 holdouts live in Nepal. It’s estimated that the global population of adult specimens has fallen below 400.

On the positive side, there have been record hatchings in recent years, and this year, 2500 hatchlings were counted on the Chambal River. Hopefully, captive breeding efforts and education initiatives will be able to replenish their numbers. Who would want to live in a world without gharials, anyway?

Penn Vet Working Dog Center
Stones, Bones, and Wrecks
New Program Trains Dogs to Sniff Out Art Smugglers
Penn Vet Working Dog Center
Penn Vet Working Dog Center

Soon, the dogs you see sniffing out contraband at airports may not be searching for drugs or smuggled Spanish ham. They might be looking for stolen treasures.

K-9 Artifact Finders, a new collaboration between New Hampshire-based cultural heritage law firm Red Arch and the University of Pennsylvania, is training dogs to root out stolen antiquities looted from archaeological sites and museums. The dogs would be stopping them at borders before the items can be sold elsewhere on the black market.

The illegal antiquities trade nets more than $3 billion per year around the world, and trafficking hits countries dealing with ongoing conflict, like Syria and Iraq today, particularly hard. By one estimate, around half a million artifacts were stolen from museums and archaeological sites throughout Iraq between 2003 and 2005 alone. (Famously, the craft-supply chain Hobby Lobby was fined $3 million in 2017 for buying thousands of ancient artifacts looted from Iraq.) In Syria, the Islamic State has been known to loot and sell ancient artifacts including statues, jewelry, and art to fund its operations.

But the problem spans across the world. Between 2007 and 2016, U.S. Customs and Border Control discovered more than 7800 cultural artifacts in the U.S. looted from 30 different countries.

A yellow Lab sniffs a metal cage designed to train dogs on scent detection.
Penn Vet Working Dog Center

K-9 Artifact Finders is the brainchild of Rick St. Hilaire, the executive director of Red Arch. His non-profit firm researches cultural heritage property law and preservation policy, including studying archaeological site looting and antiquities trafficking. Back in 2015, St. Hilaire was reading an article about a working dog trained to sniff out electronics that was able to find USB drives, SD cards, and other data storage devices. He wondered, if dogs could be trained to identify the scents of inorganic materials that make up electronics, could they be trained to sniff out ancient pottery?

To find out, St. Hilaire tells Mental Floss, he contacted the Penn Vet Working Dog Center, a research and training center for detection dogs. In December 2017, Red Arch, the Working Dog Center, and the Penn Museum (which is providing the artifacts to train the dogs) launched K-9 Artifact Finders, and in late January 2018, the five dogs selected for the project began their training, starting with learning the distinct smell of ancient pottery.

“Our theory is, it is a porous material that’s going to have a lot more odor than, say, a metal,” says Cindy Otto, the executive director of the Penn Vet Working Dog Center and the project’s principal investigator.

As you might imagine, museum curators may not be keen on exposing fragile ancient materials to four Labrador retrievers and a German shepherd, and the Working Dog Center didn’t want to take any risks with the Penn Museum’s priceless artifacts. So instead of letting the dogs have free rein to sniff the materials themselves, the project is using cotton balls. The researchers seal the artifacts (broken shards of Syrian pottery) in airtight bags with a cotton ball for 72 hours, then ask the dogs to find the cotton balls in the lab. They’re being trained to disregard the smell of the cotton ball itself, the smell of the bag it was stored in, and ideally, the smell of modern-day pottery, eventually being able to zero in on the smell that distinguishes ancient pottery specifically.

A dog looks out over the metal "pinhweel" training mechanism.
Penn Vet Working Dog Center

“The dogs are responding well,” Otto tells Mental Floss, explaining that the training program is at the stage of "exposing them to the odor and having them recognize it.”

The dogs involved in the project were chosen for their calm-but-curious demeanors and sensitive noses (one also works as a drug-detection dog when she’s not training on pottery). They had to be motivated enough to want to hunt down the cotton balls, but not aggressive or easily distracted.

Right now, the dogs train three days a week, and will continue to work on their pottery-detection skills for the first stage of the project, which the researchers expect will last for the next nine months. Depending on how the first phase of the training goes, the researchers hope to be able to then take the dogs out into the field to see if they can find the odor of ancient pottery in real-life situations, like in suitcases, rather than in a laboratory setting. Eventually, they also hope to train the dogs on other types of objects, and perhaps even pinpoint the chemical signatures that make artifacts smell distinct.

Pottery-sniffing dogs won’t be showing up at airport customs or on shipping docks soon, but one day, they could be as common as drug-sniffing canines. If dogs can detect low blood sugar or find a tiny USB drive hidden in a house, surely they can figure out if you’re smuggling a sculpture made thousands of years ago in your suitcase.

15 Confusing Plant and Animal Misnomers

People have always given names to the plants and animals around us. But as our study of the natural world has developed, we've realized that many of these names are wildly inaccurate. In fact, they often have less to say about nature than about the people who did the naming. Here’s a batch of these befuddling names.


There are two problems with this bird’s name. First, the common nighthawk doesn’t fly at night—it’s active at dawn and dusk. Second, it’s not a hawk. Native to North and South America, it belongs to a group of birds with an even stranger name: Goatsuckers. People used to think that these birds flew into barns at night and drank from the teats of goats. (In fact, they eat insects.)


It’s not a moss—it’s a red alga that lives along the rocky shores of the northern Atlantic Ocean. Irish moss and other red algae give us carrageenan, a cheap food thickener that you may have eaten in gummy candies, soy milk, ice cream, veggie hot dogs, and more.


Native to North America, the fisher-cat isn’t a cat at all: It’s a cousin of the weasel. It also doesn’t fish. Nobody’s sure where the fisher cat’s name came from. One possibility is that early naturalists confused it with the sea mink, a similar-looking creature that was an expert fisher. But the fisher-cat prefers to eat land animals. In fact, it’s one of the few creatures that can tackle a porcupine.


American blue-eyed grass doesn’t have eyes (which is good, because that would be super creepy). Its blue “eyes” are flowers that peek up at you from a meadow. It’s also not a grass—it’s a member of the iris family.


The mudpuppy isn’t a cute, fluffy puppy that scampered into some mud. It’s a big, mucus-covered salamander that spends all of its life underwater. (It’s still adorable, though.) The mudpuppy isn’t the only aquatic salamander with a weird name—there are many more, including the greater siren, the Alabama waterdog, and the world’s most metal amphibian, the hellbender.


This weird creature has other fantastic and inaccurate names: brick seamoth, long-tailed dragonfish, and more. It’s really just a cool-looking fish. Found in the waters off of Asia, it has wing-like fins, and spends its time on the muddy seafloor.


The naval shipworm is not a worm. It’s something much, much weirder: a kind of clam with a long, wormlike body that doesn’t fit in its tiny shell. It uses this modified shell to dig into wood, which it eats. The naval shipworm, and other shipworms, burrow through all sorts of submerged wood—including wooden ships.


These leggy creatures are not spiders; they’re in a separate scientific family. They also don’t whip anything. Whip spiders have two long legs that look whip-like, but that are used as sense organs—sort of like an insect’s antennae. Despite their intimidating appearance, whip spiders are harmless to humans.


A photograph of a velvet ant
Craig Pemberton, Wikimedia Commons // CC BY-SA 3.0

There are thousands of species of velvet ants … and all are wasps, not ants. These insects have a fuzzy, velvety look. Don’t pat them, though—velvet ants aren’t aggressive, but the females pack a powerful sting.


The slow worm is not a worm. It’s a legless reptile that lives in parts of Europe and Asia. Though it looks like a snake, it became legless through a totally separate evolutionary path from the one snakes took. It has many traits in common with lizards, such as eyelids and external ear holes.


This beautiful tree from Madagascar has been planted in tropical gardens all around the world. It’s not actually a palm, but belongs to a family that includes the bird of paradise flower. In its native home, the traveler’s palm reproduces with the help of lemurs that guzzle its nectar and spread pollen from tree to tree.


Drawing of a vampire squid
Carl Chun, Wikimedia Commons // Public Domain

This deep-sea critter isn’t a squid. It’s the only surviving member of a scientific order that has characteristics of both octopuses and squids. And don’t let the word “vampire” scare you; it only eats bits of falling marine debris (dead stuff, poop, and so on), and it’s only about 11 inches long.


Early botanists thought that these two ferns belonged to the same species. They figured that the male fern was the male of the species because of its coarse appearance. The lady fern, on the other hand, has lacy fronds and seemed more ladylike. Gender stereotypes aside, male and lady Ferns belong to entirely separate species, and almost all ferns can make both male and female reproductive cells. If ferns start looking manly or womanly to you, maybe you should take a break from botany.


You will never find a single Tennessee warbler nest in Tennessee. This bird breeds mostly in Canada, and spends the winter in Mexico and more southern places. But early ornithologist Alexander Wilson shot one in 1811 in Tennessee during its migration, and the name stuck.


Though it’s found across much of Canada, this spiky plant comes from Europe and Asia. Early European settlers brought Canada thistle seeds to the New World, possibly as accidental hitchhikers in grain shipments. A tough weed, the plant soon spread across the continent, taking root in fields and pushing aside crops. So why does it have this inaccurate name? Americans may have been looking for someone to blame for this plant—so they blamed Canada.

A version of this story originally ran in 2015.


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